The compound represented by Chemical Formula 38, which is a mother compound of a thymol derivative, was extracted from long tabacco grass (Carpesium divaricatum S.). It was firstly isolated and identified by Ferdinand et al. in 1961 (Chem. Ber., 102, 864-871, 1969). The intermediates of thymol were synthesized by Baliman, et al. (Tetrahedron Lett., 20, 2827-2828, 1972). ##STR3##
These thymol derivative are compounds of monoterpene derivatives, and it has been reported that terpene type compounds including monoterpenes generally show anti-tumor activity (The Journal of Biological Chemistry, 266(26), 17679-17685, Carcinogenesis 13(7), 1261-1264). The researches on the pharmacological mechanism of these compounds and developments for anti-cancer agents based on such researches have been actively performed up to the present.